📌 Quick Summary
We've tested dozens of ebook converters to find the best free options. Whether you need online convenience or desktop power, this guide covers the top choices for 2025.
Quick Comparison
| Tool | Type | Formats | Speed | Ease of Use |
|---|---|---|---|---|
| KFX Tool | Online | 30+ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ |
| Calibre | Desktop | 30+ | ⭐⭐⭐⭐ | ⭐⭐⭐ |
| Online-Convert | Online | 15+ | ⭐⭐⭐ | ⭐⭐⭐⭐ |
| Zamzar | Online | 10+ | ⭐⭐⭐ | ⭐⭐⭐⭐ |
Top Free Ebook Converters
🥇 1. KFX Tool (Online)
Our free online converter supports 30+ formats with fast conversion speeds and no registration required.
✅ Pros: Free, fast, 30+ formats, no registration, privacy-focused
❌ Cons: Requires internet connection
Best for: Quick conversions without installing software
🥈 2. Calibre (Desktop)
The most powerful free ebook management software. Open source and feature-rich.
✅ Pros: Extremely powerful, library management, metadata editing, plugins
❌ Cons: Steeper learning curve, requires installation
Best for: Power users with large ebook collections
🥉 3. Online-Convert.com
Popular online conversion platform with good format support.
✅ Pros: Easy to use, multiple format types
❌ Cons: Ads, file size limits on free tier
Best for: Occasional conversions
Choosing the Right Converter
Choose Online Converters When:
- You need quick, occasional conversions
- You don't want to install software
- You're on a shared or restricted computer
- You need to convert from mobile devices
Choose Desktop Software When:
- You convert ebooks frequently
- You need advanced customization
- You manage a large ebook library
- You work with very large files
Supported Formats
Most converters support these common formats:
- EPUB: Universal ebook standard
- MOBI/AZW: Amazon Kindle formats
- PDF: Universal document format
- DOCX: Microsoft Word documents
- TXT: Plain text files
- AZW3: Kindle Format 8
- FB2: FictionBook format
- RTF: Rich Text Format
Tips for Best Results
- Start with well-formatted source files
- Check the output on your target device
- Use appropriate metadata (title, author)
- Include a cover image when possible
- Test with a small file first